Click on the link.
You can see the fuses, not only check the fuse, check for voltage on fuse circuit, use a test light, goes hot with key on.
On the hinge side of driver door, check the wiring harness. Probably has a protective rubber boot covering, see if you can pull the boot back far enough to get at the proper color. Green wire with blue tracer should be voltage, with key on, use a test light. Also, check the ground wire, it is black. You can use a test light to check ground also. One end of test light touches battery voltage, the other end penetrates that black wire, if the light comes on, the ground is good enough for test light. The driver door is opened and closed so much, sometimes the wires break. If you make a hole in the wire, use finger-nail polish or something to cover the hole.

Here is how this works. A coolant sensor triggers the "cold start" sequence which raises engine idle, enriches the fuel ratio, and makes a few other adjustments. When problems like yours occurs it means the engine is stuck in warm mode or the engine controls are ignoring the signal to reset. The cheaper part is the coolant sensor.

You might have a power trunk button try to look for it also you should download your owners manual at ford owners.Com it should give you the location and your fuse box diagrams and other information now the seat you will have to unbolt it the side panels pop out and are held in with clips the bottom of the seat may pop out by pushing inwards but this also could be bolted in look around the bottom also when you pop out the side panels you might gain accessories to the rear deck bolts that the third brake light is attached to and radio speakers if applicable anyway you should be able to axcess the trunk by this path it's going to be a pain in the gozompus but you can get in I don't own a focus but from memory of getting stuff in junk yards I'm trying to help you so excuse me if I'm wrong here or there so pull out the door seals that go around the door opening there might be panel bolts in the frame and seat bolts behind once you get to them you should be able to get to the levers also I know that the lock was possibly frozen when you put in the key knocking in the weather shield and jamming the lock cylinder you can try putting the key in and keep trying to turn it while banging the trunk where the cylinder is and you might jar it loose that metal flap has a spring on it and those 2 things are stopping the key from turning the other alternative is to try using a very small screwdriver to try to move it out of the way so the key will turn you have to be gentle here digging in like crazy will not help and last of all if you can't get in then use a drill and destroy the cylinder completely and a long screwdriver and a hammer will get you in you'll have to change the cylinder anyway so whack away at it if all else fails good luck stephen